CN110267909A

CN110267909A - Core shell

Info

Publication number: CN110267909A
Application number: CN201880009912.1A
Authority: CN
Inventors: 周南翰; 瑞恩·麦肯尼; 克里斯多夫·布鲁克斯
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2017-02-02
Filing date: 2018-02-02
Publication date: 2019-09-20
Anticipated expiration: 2038-02-02
Also published as: JP2020507452A; US10675681B2; US20180214945A1; DE112018000318B4; WO2018144895A1; JP6952783B2; DE112018000318T5; CN110267909B

Abstract

The invention discloses Multifunctional core@core-shell nanoparticles (CSN), can be used for electrochemical cell, are used specifically as electrocatalyst materials.Multi-functional CSN includes the catalysis core assembly surrounded by one or more shells.It further include electrochemical cell electrode and electrochemical cell and their preparation method, the electrochemical cell electrode and electrochemical cell carbon dioxide is electrochemically transformed be for example useful fuel (such as, synthetic fuel) or other products, and include multi-functional CSN.

Description

Core shell

Cross reference to related applications

Patent application claims the U.S. Provisional Patent Application No. submitted for 2nd 62/453,877 and 2018 year 2 months 2017 The priority for the U.S. Provisional Patent Application No. 15/886,635 submitted for 1st for 2 months, disclosures of these patents full text is to quote Mode is incorporated herein.

Technical field

The present disclosure relates generally to for the electrochemical cell by carbon dioxide conversion at useful products.Electrochemical cell includes Electrode with the Multifunctional core@core-shell nanoparticles for providing high-caliber catalytic activity, selectivity of product and stability, and system The method of the standby electrode.

Background technique

The electrochemical system for restoring carbon dioxide when energized provides attractive power supply selection, because they can not only The discharge of carbon dioxide (main greenhouse gas) is enough offset, but also can be useful with other at fuel by carbon dioxide conversion Product.However, such electrochemical cell proposes main technological challenge, and such as low catalytic activity, selectivity of product, And for the stability of electrode etc. in such system.Although having studied nearly all pure metal and its conjunction Gold is used as elctro-catalyst in carbon dioxide reduction, but there is currently no the electrode materials for overcoming all above-mentioned challenges.Therefore, originally Field needs to provide the electrode material of high-caliber catalytic activity, selectivity of product and stability.

Summary of the invention

The present disclosure relates generally to can be used for electrochemical cell, the Multifunctional core@shell for being used specifically as electrocatalyst materials is received Rice grain (CSN).It include the catalysis core assembly surrounded by one or more shells according to the multi-functional CSN of the disclosure.This public affairs It opens and also relates generally to electrochemical cell electrode and electrochemical cell, the electrochemical cell electrode and electrochemical cell are by carbon dioxide Being electrochemically transformed is for example available fuel (for example, synthetic fuel) or other products, and it includes more function as described herein It can CSN.

The disclosure also relates generally to the method for preparing multi-functional CSN as described herein.

The disclosure also relates generally to electronation CO₂Method.According to some aspects, this method may include providing electrochemistry Battery, the electrochemical cell include anode, cathode and liquid electrolyte, and wherein cathode includes electro-catalysis component, the electro-catalysis group Subpackage is containing at least one CSN according to the disclosure；CO is provided₂Source；And reduction CO₂。

Detailed description of the invention

Fig. 1 a is to show the sectional view that core assembly is catalyzed according to the illustrative solid of the CSN of all aspects of this disclosure.

Fig. 1 b is to show to be catalyzed cuing open for core assembly according to the illustrative solid of the cated CSN of tool of all aspects of this disclosure Face figure.

Fig. 1 c is to show the sectional view that core assembly is catalyzed according to the exemplary hollow of the CSN of all aspects of this disclosure.

Fig. 2 is the sectional view for showing the multi-functional CSN according to all aspects of this disclosure.

Fig. 3 a is the multi-functional CSN for showing the shell with fully covering catalysis core assembly according to all aspects of this disclosure Sectional view.

Fig. 3 b is the multi-functional CSN with the shell for partly covering catalysis core assembly shown according to all aspects of this disclosure Sectional view.

Fig. 4 is the sectional view for showing the electrochemical cell according to all aspects of this disclosure.

After Fig. 5 shows immediately synthesis and separates (" obtained as it is "), the isolated copper of the comparative example 1 without shell The XRD of nano particle is composed.

Fig. 6 shows obtained as it is and is being exposed to air 4 days and after 9 days, the comparative example 1 without shell divides From copper nano particles stacking XRD spectrum.

Fig. 7 shows the XRD spectrum of the Cu-LaF3 CSN of the experimental example 1 synthesized such as an aspect of this disclosure.

Fig. 8 shows the stacking of the Cu-LaF3 CSN of the experimental example 1 after being exposed to air 9 days, 16 days and 23 days XRD spectrum.

Fig. 9 A and Fig. 9 B are transmission electron microscope (TEM) figure of the Cu-LaF3 CSN of experimental example 1 obtained as it is Picture.

Figure 10 A shows the high-resolution TEM image of the Cu-LaF3 CSN of experimental example 1, instruction (core) region Cu and LaF3 (shell) region.Figure 10 B and Figure 10 C show the zoomed image of identical nano particle.

Figure 11 shows the XRD spectrum of the Cu-Cu2O-LaF3 CSN of the experimental example 2 synthesized such as an aspect of this disclosure.

Figure 12 shows the XRD spectrum of the Cu2O-LaF3 CSN of the experimental example 3 synthesized such as an aspect of this disclosure.

Figure 13 shows the XRD spectrum of the nano particle of the comparative example 2 of synthesis.

Figure 14 shows the stacking XRD of the nano particle of the comparative example 2 after being exposed to air 8 days, 15 days and 22 days Spectrum.

Figure 15 is the TEM image of the nano particle of comparative example 2, and it illustrates copper nano particles by the non-uniform part LaF3 Covering, and the not LaF3 with copper nano particles association.

Figure 16 be comparative example 3 nano particle TEM image, show Cu nano particle be broken down into it is Cu nanometers lesser Particle, and core shell structure is not formed.

Figure 17 shows the current densities of the CSN of experimental example 4.

Figure 18 A shows the CO of the CSN of experimental example 4₂Absorption.

Figure 18 B shows the CO of the CSN of experimental example 4₂Absorption.

Figure 19 A shows the gaseous product as made from the catalyst studied in experimental example 4.

Figure 19 B shows the alcohol product as made from the catalyst studied in experimental example 4.

Figure 20 shows the current density of the CSN of experimental example 5.

Figure 21 A shows the CO of the CSN of experimental example 5₂Absorption.

Figure 21 B shows the CO of the CSN of experimental example 5₂Absorption.

Figure 22 shows the alcohol product as made from the catalyst studied in experimental example 5.

Specific embodiment

The present disclosure relates generally to can be used for electrochemical cell, it is used specifically as the multi-functional CSN of electrocatalyst materials.According to The multi-functional CSN of the disclosure may include the catalysis core assembly surrounded by one or more shells.The disclosure also relates generally to electrification It learns battery electrode and carbon dioxide is electrochemically transformed as other by electrochemical cell, the electrochemical cell electrode and electrochemical cell Product, and it includes multi-functional CSN as described herein.

As used herein, term " CSN " refers to the nanoscale with the catalysis core assembly surrounded by one or more shells Grain.The multi-functional CSN of the disclosure can advantageously improve electro-catalysis battery in carbon dioxide electro-catalysis reduction effect and/or There is multi-function action in terms of efficiency.For example, the multi-functional CSN of the disclosure can by provide have high-caliber catalytic activity, The electrode containing catalyst of selectivity of product and/or stability come improve carbon dioxide electro-catalysis reduction effect and/or effect Rate.

It include the catalysis core assembly surrounded by one or more shells according to the multi-functional CSN of the disclosure, wherein being catalyzed core Component includes one or more catalysis materials.As used herein, " catalysis material ", which refers to, can be used for causing or accelerate (that is, " urging Change ") chemical reaction material.For example, it is for example useful that catalysis material, which can be at least partly catalysis carbon dioxide conversion, The material of fuel or other products.

Example according to the available catalysis material of the disclosure include but is not limited to metal (for example, copper, cobalt, iron, nickel, lead and Tin) and/or their alloy and/or oxide.

As used herein, term " catalysis core assembly " refers to the interior section of CSN.According to some aspects, it is catalyzed core assembly It can be solid core component.As used herein, term " solid " means non-hollow.As shown in Figure 1a, solid core assembly 10 can wrap Containing one or more catalysis materials 11.For example, solid core assembly may include the first catalysis material, such as metal.

As shown in Figure 1 b, solid core assembly 10 also may include the second catalysis material 12 for coating the first catalysis material 11.Example Such as, coating may include metal oxide.According to some aspects, coating can be by heating the first catalysis material in air, electrification The outer layer of the first catalysis material of oxidation is learned, and/or the second depositing catalytic material is formed on the first catalysis material.The coating can Being completely covered of first catalysis material (that is, surface region of the first catalysis material of covering 100%) is provided or can provide first The part covering (that is, surface region of first catalysis material of the covering less than 100%) of catalysis material.

According to some aspects, it is not solid for being catalyzed core assembly.For example, catalysis core assembly can be hollow, such as in Empty sphere.As illustrated in figure 1 c, hollow core assembly 14 may include one or more catalysis materials 13.For example, hollow core assembly can wrap Containing metal oxide.

According to some aspects, being catalyzed core assembly can be surrounded by one or more shells.As shown in Fig. 2, CSN 20 may include Shell 23, the shell surround catalysis core assembly 21, and catalysis core assembly can be any in catalysis core assembly as described herein Kind.

Shell can provide being completely covered of CSN (that is, surface region of the catalysis core assembly of covering 100%).For example, as schemed Shown in 3a, CSN 30 may include solid catalysis core assembly and shell 33, and solid catalysis core assembly has 31 He of the first catalysis material Second catalysis material coating 32, the whole surface region of shell covering catalysis core assembly.

Alternatively, shell can provide the part covering of CSN (that is, the surface district of catalysis core assembly of the covering less than 100% Domain).For example, as shown in Figure 3b, CSN 30 may include the shell of a part of solid catalysis core assembly and covering catalysis core assembly 34, which has the first catalysis material 31 and the second catalysis material coating 32, the part of covering herein Referred to as shell percentage of coverage.

Shell can cover the surface region of at least 90% catalysis core assembly (that is, CSN can have at least 90% shell covering Rate), the surface region of at least 80% catalysis core assembly, the surface region of at least 70% catalysis core assembly, at least 60% It is catalyzed the surface region of core assembly, the surface region of at least 50% catalysis core assembly, the table of at least 40% catalysis core assembly Face region, the surface region of at least 30% catalysis core assembly, the surface region of at least 20% catalysis core assembly, or at least The surface region of 10% catalysis core assembly.

According to some aspects, shell percentage of coverage may be selected to provide optimum performance.As used herein, term " optimality Can " refer to the performance of the capacity for selected performance parameter for or close to CSN.For example, optional shell covers according to some aspects Lid percentage is to provide optimum current density.Additionally or alternatively, shell percentage of coverage may be selected and lived with providing best catalysis Property, for example, optimal CO₂Absorption and/or CO₂To certain gases and/or alcohol product (including but not limited to, ethyl alcohol, normal propyl alcohol, with And their combination) selective conversion rate.It should be appreciated that shell percentage of coverage needed for providing optimum performance can be based on CSN Certain characteristics (for example, property of catalysis core assembly and/or shell) and change.

It include LaF according to some aspects₃The shell percentage of coverage of the CSN of shell can be about 25% to 45%, optionally about 30% to 40%, optionally about 31% to 37%, optionally about 32% to 36%, optionally about 33% to 36%%, and optionally Ground about 34%.

According to some aspects, include La (OH)₃The shell percentage of coverage of the CSN of shell can be about 1% to 20%, optionally About 5% to 15%, optionally about 6% to 14%, optionally about 6% to 13%, optionally about 8% to 12%, optionally about 9% To 11%, and optionally about 10%.

According to some aspects, shell percentage of coverage can correspond to one or more steps in CSN synthetic method.For example, According to some aspects, shell percentage of coverage can correspond at least partially to the amount and/or concentration of the raw material for providing shell.

For example, including LaF₃In the CSN of shell, shell percentage of coverage can be corresponded at least partially to for providing LaF₃Shell La (NO₃)₃-6H₂The concentration of O and/or NaF.In a non-limiting example, the La (NO of about 1mmol₃)₃-6H₂O and The NaF of 1mmol can provide about 18% shell coverage rate.In another non-limiting example, the La (NO of about 2mmol₃)₃-6H₂O It can provide about 34% shell coverage rate with the NaF of 2mmol.In another non-limiting example, the La (NO of about 4mmol₃)₃- 6H₂The NaF of O and 4mmol can provide about 50% shell coverage rate.

In another example, including La (OH)₃In the CSN of shell, shell percentage of coverage can correspond at least partially to use In offer La (OH)₃La (the NO of shell₃)₃-6H₂The concentration of O and/or hydrazine hydrate.In a non-limiting example, about La (the NO of 0.1mmol₃)₃-6H₂The hydrazine aqueous solution (volume of water is adjusted to be equal to 30mL in total) of O and about 1.5mL can provide About 10% shell coverage rate.In another non-limiting example, the La (NO of about 1mmol₃)₃-6H₂The hydrazine of O and about 2mL are water-soluble Liquid (volume of water is adjusted to be equal to 30mL in total) can provide about 24% shell coverage rate.In another non-limiting example In, the La (NO of about 2mmol₃)₃-6H₂The hydrazine aqueous solution (volume of water is adjusted to be equal to 30mL in total) of O and about 3mL can provide About 47% shell coverage rate.

It should be appreciated that one or more of shell percentage of coverage value as described herein can correspond to assess.According to some Aspect, the assessment working model obtain, and wherein the model is based at least partially on the shape of CSN and/or its component, size And/or thickness.For example, working model assesses full shell coverage rate (that is, 100% shell coverage rate), then the full shell of assessment is covered Lid rate be made of CSN shell material (or part thereof) amount be compared to determine shell percentage of coverage, wherein shell material (or Its part) amount use one or more measuring devices known in the art and/or technology, such as inductively coupled plasma body (ICP) technology and/or Energy dispersive x-ray spectrum (EDS) technology measure.

Shell may include the shell material with certain desired characteristics, specifically when for carbon dioxide to be electrochemically transformed When in the electrochemical cell of fuel, polymer and/or other products.One desired characteristic of shell material can be itself and two The interaction of carbonoxide and/or carbanion.For example, shell material can be with carbon phase interaction, so that carbon dioxide and/or carbon Acid ion is absorbed via strong chemical bond and/or is chemically adsorbed on the surface CSN.This interaction can also be on the surface CSN The carbon dioxide and/or carbanion of single single layer type are provided.For example, not having the nanoparticle catalyst of shell material It can express with a series of binding patterns of carbon dioxide and/or carbanion (for example, bending is combined, linear combination, oxygen knot Close and/or carbon be integrated to catalytic surface), however can express single binding pattern according to the CSN of the disclosure.The characteristic at least portion The local concentration of the carbon dioxide and/or carbanion on the surface CSN can be increased with dividing and/or works as and do not have shell material When nano particle is compared, carbon dioxide and/or carbanion absorption and/or be chemisorbed on the surface CSN time quantum (because This, increases the concentration that can be used for being catalyzed carbon dioxide and/or carbanion that core assembly is catalyzed).The characteristic can also help It is specific in improving reaction product.Therefore, shell material can for example facilitate to overcome and carbon dioxide in aqueous electrolyte compared with The problem of poor solubility correlation, and enhance catalytic activity and the spy of the reaction product generated by such electrochemical cell It is anisotropic.

Another desired characteristic of shell material can adjust the pH on the surface of CSN for it.For example, CSN is adjusted in shell material The basicity on surface.Such pH adjust the absorption that can for example influence carbon dioxide and/or carbanion on the surface of CSN and/ Or chemisorption (carbon dioxide/carbanion concentration that can be used for being catalyzed core assembly catalysis therefore, can be influenced).

Another desired characteristic of shell material can be the combination energy of reduction reaction intermediate and CSN.For example, by having Height combines the reaction of the catalyst of the reaction intermediate of energy usually than having the reaction of the catalyst compared with low combination energy Need more energy.By reducing the combination energy of reaction intermediate, therefore shell material can react required energy by reducing It measures to improve the catalytic activity of catalysis core assembly.

Another desired characteristic of shell material can be its influence to electron inversion.For example, shell material may include having Conducive to the component of swift electron reversion, compared with the catalyst nano-particles for not having shell material, catalysis core assembly is can be improved in this To titanium dioxide charcoal percent conversion.

Shell material can have some or all of above-mentioned characteristic.

Shell material may include halogen.Halogen for example can form strong chemical bond with carbon.According to some aspects, halogen can be by The anion of halide and/or ternary compound is constituted.For example, shell material may include fluoride and/or oxyfluoride.

Shell material may include oxygen.According to some aspects, oxygen atom can by anion, such as oxide, hydroxide and/or The anion of oxyfluoride is constituted.

Shell material also may include metal.For example, metal is capable of providing redox couple, be conducive in carbon dioxide reduction The reversion of period swift electron.According to some aspects, metal can be by halide, oxide, hydroxide and/or ternary compound Cation is constituted.The example for the metal that can be used in shell material includes but is not limited to lanthanum, calcium, cerium, magnesium and manganese.

Shell material may include organic molecule.As used herein, term " organic molecule " refers in ring and/or chain comprising one Molecule of a or multiple carbon atoms together with other one or more atoms (such as hydrogen, oxygen and nitrogen) bonded thereto.

Example according to the useful shell material of the disclosure includes but is not limited to LaF₃、La(OH)₃、CeF₃、CaF₂、MgF₂、 MeF₃、LaOF、CeOF、La₂O₃、CeO₂, organic molecule (including for example, include one or more amine (NH₂) organic point of group Son) and their combination.

All aspects of this disclosure also relate generally to the electrochemical cell comprising multi-functional CSN as described herein and electrochemistry electricity Pond electrode.In particular, as shown in figure 4, the electrochemical cell 40 of the disclosure can include at least the yin comprising multi-functional CSN 42 Pole 41, anode 43 and liquid electrolyte 44, and can when battery is powered by carbon dioxide conversion at useful product (such as Fuel, polymer etc.).For example, electrochemical cell can by carbon dioxide reduction at carbon monoxide, C2-C3 alkane, C2-C3 alkene, C2-C3 alcohol, C2-C3 carboxylic acid, C2-C3 aldehyde or their combination.According to some aspects, electrochemical cell is energized but does not generate Any additional carbon dioxide.

Electrochemical cell may include electrode (for example, cathode), and electrode includes elctro-catalyst, specifically comprising such as this paper institute The elctro-catalyst of the CSN stated.The electrode of the disclosure shows certain distinctive characteristics better than previously known electrode.For example, with this Other electrodes known to field are compared, and electrode according to the present invention can express higher catalytic activity, stability and selectivity. These distinctive characteristics can at least partly be caused by the catalysis core assembly of CSN and the combination of one or more shells.

For example, the electrode of all aspects of this disclosure can express the stability more high than known electric, this is at least partly Due to the shell of CSN.For example, shell can protect catalysis core assembly from the corrosion of electrolyte solution and/or inhibit evolving hydrogen reaction. Shell can also reduce or inhibit the Carbon deposition and/or metal deposit of the impurity in electrolyte, this can be dropped over time Low catalytic performance.The electrode of the disclosure also can express higher catalytic activity and/or selectivity, this is at least partly due to The desired characteristic of shell material as described herein.

According to some aspects and as described above, certain characteristics of CSN can be by such as shell covering on catalysis core assembly Lid amount (that is, shell percentage of coverage) causes.

For example, if the surface region of the catalysis core assembly of shell covering 100%, CSN can express high stability (protecting catalysis material from inactivating or being poisoned that is, maximizing), this is because maximizing the high chemistry of chemisorption/adsorption site Absorption/absorption, and a large amount of redox reaction sites.If covering to casing part the surface region of catalysis core assembly, Compared with being completely covered, more exposed active site may be present, and (therefore, may be present can be catalyzed carbon dioxide reduction More active sites).

All aspects of this disclosure further relate to the method for preparing component as described herein, and use CSN as described herein, electricity The method that carbon dioxide is electrochemically converted into useful products by pole and/or electrochemical cell.

For example, the method for being used to prepare CSN may include by catalysis material nano particle, reducing agent, metal salt and fluoride Salt mixing, to form the painting comprising metal halide shell or metal oxyhalide shell around the core comprising catalysis material nano particle The metal nanoparticle covered.

Catalysis material may include one or more metals.The metal for being used to form core can be by by metal precursor solutions and also Former agent is mixed to form metal nanoparticle to synthesize.

In some embodiments, the metal nanoparticle for being used to form core can synthesize in the presence of stabilizer, surely Determine the oxidation that agent prevents during synthesis or otherwise inhibits metal nanoparticle, and is formed on metal halide It is easy to remove from metal nanoparticle before shell or metal oxyhalide shell.For example, being used during metal nanoparticle synthesis Bulk polymer such as polyvinylpyrrolidone (molecular weight 55,000g/mol) inhibit metal nanoparticle oxidation.So And such stabilizer is not easy to remove from metal nanoparticle in post synthesis.It is not being bound by any particular theory, remaining stabilizer Extra play can be formed between the core formed by metal nanoparticle and metal halide shell or metal oxyhalide shell, this reduction The performance of CSN in required system.

Therefore, stabilizer can be used for synthesizing the metal nanoparticle for being used to form core, and stabilizer is easy to remove from core, with Minimize the amount of the stabilizer on the surface of core before directly forming metal halide shell or metal oxyhalide shell on it. In a non-limiting example, one or more stabilizers can be used for synthesizing metal nanoparticle, and stabilizer includes being less than 1000g/mol, optionally less than 500g/mol, optionally less than 375g/mol, and the molecule of optionally less than 350g/mol It measures (independent molecular weight or weight average molecular weight).Illustrative examples include the cetyl trimethyl bromination that molecular weight is 364g/mol Ammonium (CTAB), the citric acid and their mixture that molecular weight is 192g/mol.

Can by will be used to form the isolated metal nanoparticle of core with for example react with by metal halide shell The metal salt solution and halide salt aqueous solution being deposited directly on core mix to form the shell of CSN.Shell can entirely around core or its Core can only partially be covered.In some embodiments, be used to form shell metal salt be selected from alkali metal salt, alkali salt and Transition metal salt.In certain embodiments, the metal salt for being used to form shell is transition metal salt.In certain embodiments, The metal salt for being used to form shell is selected from lanthanum salt, cerium salt and magnesium salts.In certain embodiments, the metal salt for being used to form shell is selected from Lanthanum salt and cerium salt.In certain embodiments, metal salt is lanthanum salt.In a preferred embodiment, lanthanum salt is lanthanum nitrate. In some embodiments, halide salts are sodium fluoride.

In other embodiments, this disclosure relates to the electrode comprising CSN disclosed herein.About CSN and its preparation All aspects and embodiment that method is described are equally applicable to electrode.In a non-limiting example, electrode is For by carbon dioxide conversion at the cathode in the electrochemical cell of Organic Ingredients." inert atmosphere " refers to admixture of gas, Comprising seldom or not including oxygen and including one or more inert gases or non-reactive gas, have before they are reacted High threshold.Inert atmosphere can be but not limited to dinitrogen or inert gas, such as argon gas or their mixture.

" reducing agent " is the substance for leading to another substance reduction while its own is oxidized.Reduction refers to chemicals The gain of confrontation electronics, oxidation refer to loss of the chemical substance to electronics.

" metal salt " is ionic complex, wherein cation is positively charged metal ion, and anion is negatively charged Ion." cation " refers to positively charged ion, and " anion " refers to electronegative ion.According to the disclosure In " metal salt ", anion can be any electronegative chemical substance.May include according to the metal in the metal salt of the disclosure But it is not limited to alkali metal salt, alkali salt, transition metal salt, aluminium salt or late transition metal salt and their hydrate.

" alkali metal salt " is metal salt, and wherein metal ion is the gold in the group i of alkali metal ion or the periodic table of elements Belong to, such as lithium, sodium, potassium, rubidium, caesium or francium.

" alkali salt " is metal salt, and wherein metal ion is the group ii of alkaline-earth metal ions or the periodic table of elements In metal, such as beryllium, magnesium, calcium, strontium, barium or radium.

" transition metal salt " is metal salt, and wherein metal ion is in the area d of transition metal ions or the periodic table of elements Metal, including lanthanide series and actinides.Transition metal salt includes but is not limited to the salt of following metal: scandium, titanium, vanadium, chromium, Manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, Dysprosium, holmium, erbium, thulium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, Einsteinium, fermium, mendelevium, nobelium and lawrencium.

" late transition metal salt " is metal salt, wherein metal ion be late transition metal ion, such as gallium, indium, tin, thallium, Lead, bismuth or polonium.

" fluoride salt " is the ionic complex that wherein anion is fluorine ion.According to the disclosure, the sun of fluoride salt from Son can be any positively charged chemical substance.

" metal fluoride " is that wherein cation is metal ion and anion is the ionic complex of fluorine ion.According to The disclosure, metal salt and fluoride salt reaction are to generate metal fluoride shell around metal nanoparticle core.

Term " electrochemical cell " refers to the device and/or device feature for being conducive to chemical reaction by introducing electric energy. Electrochemical cell has two or more electrodes (for example, anode and cathode) and electrolyte.

Although having been combined above-mentioned each illustrative aspect describes various aspects described herein, various alternative arrangements are repaired Change, modification, improvement and/or substantially equivalent form (either known or unpredictalbe at present or may be unpredictalbe) It may become apparent from least those of ordinary skill in the art.Therefore, as it appears from the above, each illustrative aspect is intended to It is illustrative rather than restrictive.Various changes can be carried out in the case where not departing from the spirit and scope of the disclosure.Therefore, The disclosure is intended to cover alternative arrangement, modification, modification, improvement and/or substantially equivalent form all known or develop later.

Therefore, claim is not intended to be limited to aspects shown herein, and is to confer to meet the language of claims The full scope of speech, wherein unless specifically stated otherwise, refer to that element is not intended to expression " one and only one " in the singular, but " one or more ".Various aspects described in the disclosure that will be recognized known to those skilled in the art or later are wanted All structure and function equivalent forms of element are clearly herein incorporated by reference, and are intended to be contained by claims Lid.In addition, any content disclosed herein is not intended to dedicated to the public, no matter whether clearly chat in detail in the claims Such disclosure is stated.Unless clearly listing the element using phrase " meaning ", otherwise any claim elements are equal The mode of being not to be construed as adds function.

In addition, word " example " is used herein to mean that " being used as example, example or illustration ".It is described herein as " example " Any aspect shall not necessarily be understood as being it is preferably or more advantageous than other aspects.Unless stated otherwise, otherwise term "some" Refer to one or more.Combine such as " at least one of A, B or C ", " at least one of A, B and C " and " A, B, C or it Any combination " include any combination of A, B and/or C, and may include the multiple of the multiple of A, the multiple of B or C.Specifically Ground says, combines such as " at least one of A, B or C ", " at least one of A, B and C " and " A, B, C or their any group Close " it can be only A, be only B, be only C, A and B, A and C, B and C or A and B and C, the such combination of any one of them may include A, one or more members in B or C.Any content disclosed herein is not intended to dedicated to the public, no matter wants in right It asks and whether has enunciated such disclosure in book.

Following embodiment is shown so as to provided to those skilled in the art how to manufacture and use it is of the invention complete Whole disclosure and explanation, and it is not intended to be limited to the range that the present inventor is regarded as its invention, it is complete for being not intended to and showing following experiment Portion or the experiment uniquely carried out.Have made efforts to ensure using number (for example, amount, size etc.) accuracy, but it should considering one A little experimental errors and deviation.

It I. include the CSN of metal core and metal halide shell or metal oxyhalide shell

In one embodiment, CSN is provided comprising at least partly by metal halide shell or metal zirconyl oxyhalides The metal core that object shell surrounds.

In one illustrative example, halide shell is provided, is customized to protect metal core nano particle from electricity The influence in polar ring border, while keeping the expected performance of metal nanoparticle.In a non-limiting example, core may include copper gold Belong to, and shell may include LaF₃。

The method for preparing CSN may include provide include metal nanoparticle and reducing agent the first mixture, and by the One mixture mixed with the solution comprising metal salt and halide salts on metal nanoparticle formed metal halide shell or Metal oxyhalide shell.

The synthesis and separation of I (a) metal core

In general, the metal nanoparticle as metal core can be by making gold in the presence of one or more stabilizers Belong to salting liquid to be reacted with reducing agent to synthesize.In one illustrative example, metal salt solution includes the nitric acid as metal salt Half pentahydrate (Cu (NO of copper (II)₃)₂·2.5H₂O).Metal salt is mixed with CTAB and water, and the pH of mixture can use-case As ammonium or sodium hydroxide are adjusted to about 10 to 11 pH.

Before reducing agent is added in metal salt solution, reducing agent can be mixed with one or more stabilizers and water, And a period of time is mixed before mixing with metal salt solution, such as 20 minutes.Reducing agent is selected from: hydrazine, sodium borohydride, cyanogen Base sodium borohydride, even two sulphonic acid sodiums, ferric sulfate (II), stannic chloride (II), potassium iodide, oxalic acid, formic acid, resist sodium sulfite Bad hematic acid, thiosulfate, dithionate, phosphoric acid, phosphite and hypophosphites.In a preferred embodiment In, reducing agent is hydrazine.

Metal salt solution and reducing agent are mixed to form metal nanoparticle.The synthesis of metal nanoparticle is not oxygen-containing Atmosphere in carry out.The illustrative examples of oxygen-free atmosphere include but is not limited to nitrogen, argon gas, helium, hydrogen and they Mixture.After synthesis, metal nanoparticle is separated with synthetic solvent.It should be appreciated that the method for separation metal nanoparticle It is unrestricted, and may include one or more technologies, it such as filters, decant and is centrifuged.Metal nanoparticle can be all with solvent If ethanol washing is one or many, to remove the stabilizer or other organic materials of any remnants from its surface.

I (b) hull shape at

In general, isolated metal nanoparticle can be redispersed under oxygen-free atmosphere comprising Additional reductant Aqueous solution in.Then under oxygen-free atmosphere, by mixture and use comprising isolated metal nanoparticle and reducing agent In the metal salt solution and halide salt aqueous solution mixing that form metal halide shell on metal nanoparticle core.It can will be used for shape The metal salt solution and fluoride salt solution of shelling sequentially add in mixture of nanoparticles, or the metal salt that will be used to form shell Solution and fluoride salt solution are added in mixture of nanoparticles simultaneously.

I (c) comparative example 1 and experimental example 1

In comparative example 1, prepares the copper nano particles without shell and analyzed.Firstly, at room temperature by 2mmol's Cu(NO₃)2·2.5H₂The CTAB of O and 1.87mmol is dissolved in 75ml water, and adds 0.5ml NH₄OH (28 weight % to 30 The NH of weight %₃Aqueous solution, 14.8M) pH is adjusted to about 10 to 11.Prepare under argon gas comprising hydrazine (the 50% of 3ml to 60% SILVER REAGENT), water (75ml) solution of CTAB (1.87mmol) and citric acid (0.38mmol) and mix about 20 minutes, so After add copper nitrate solution.Reaction mixture is stirred 1.5 hours, so that copper nano particles growth maximizes.It separates and washs Resulting copper nano particles (~50nm).In particular, reaction synthetic mixture to be centrifuged, decantation, mix simultaneously ultrasound with ethyl alcohol Processing.Fig. 5 shows X-ray diffraction (XRD) spectrum of copper nano particles made from original sample.Three peaks can be observed, it is all right It should be in Cu (° 2 θ): 43.0,50.5 and 74.0.However, when exposed to air, Cu is oxidized to Cu₂O, at least as early as 4 days When begin to be formed, and be the primary product after 9 days.This shows in Fig. 6, and it illustrates in 29.5,42.3,61.3 and The appearance at new peak at 73.5 ° of 2 θ corresponds to Cu₂O。

In experimental example 1, CSN is prepared for according to the disclosure comprising core, core include to be coated with to include lanthanum fluoride (Cu/ LaF₃) shell copper nano particles.Using method preparation~50nm copper nano particles identical with comparative example 1, but analyzing And after washing copper nano particles, it is redispersed in the hydrazine (the 50%-60% SILVER REAGENT of 3ml) of water and 3ml under an argon atmosphere. La (NO is added in the mixture of Xiang Shui, copper nano particles and hydrazine₃)3·6H₂The solution of O is (in 15ml H₂1mmol in O) and NaF Solution (in 15ml H₂1mmol in O).Reaction mixture is stirred 10 minutes, and is then centrifuged for.

Precipitating passes through XRD analysis by centrifuge separation.The XRD spectrum of the CSN of synthesis is shown in Figure 7.XRD spectrum shows 5 A peak (° 2 θ): 25.0 (LaF3), 28.0 (LaF3), 43.5 (Cu), 50.4 (Cu), 74.0 (Cu).Fig. 8, which is shown, to be exposed to The stacking XRD spectrum of CSN at air 9 days, 16 days and 23 days.Compared with comparative example 1, do not observe that map changes.Fig. 9 A and Fig. 9 B The TEM image of the CSN of synthesis is shown.As shown, copper nano particles core is by LaF₃Shell covering.Shell has about 0.30 nanometer of thickness Degree.Figure 10 A to Figure 10 C shows the high-resolution TEM image of the CSN of synthesis.Central black region corresponds to copper core, and periphery Black and white region corresponds to LaF₃Shell.Attached drawing shows copper core by LaF₃Shell uniform fold.

Therefore, the CSN synthesized in experimental example 1 provides the shell that can protect following metal core.Such CSN can be used for it Middle operating condition is dissolvable, aoxidizes or in other words pollute the application of metal core.Illustrative examples include CSN as with electrochemistry The cathode of battery is used for together by CO₂It is converted to the purposes of the catalyst of Organic Ingredients.

II. the CSN of metal halide shell or metal oxyhalide shell comprising the modified core of modified metal core and covering

In some applications, it may be desirable to which the core includes metal oxide.In one embodiment, CSN is provided comprising Core and shell, core include the metal nanoparticle of the oxide coated with metal nanoparticle, and shell includes at least partly around gold Belong to the metal halide or metal oxyhalide of the metal oxide layer of core.

It in one illustrative example, can include CSN in the electrode of electrochemical cell to be used for carbon dioxide conversion At Organic Ingredients.Without being bound by any particular theory, core can be improved by metal oxide layer being formed on the outer surface of metal core The selectivity and catalytic activity of shell catalyst in an electrochemical cell.It can be controlled during the synthesis of nanoparticle core and/or shell The formation of metal oxide layer and the state of oxide are to generate desired specificity of catalyst.

The method for preparing CSN may include metal oxide layer being formed on metal nanoparticle, and use metal halide Or metal oxyhalide shell coated metal oxide layer, metal halide or metal oxyhalide shell are by the solution comprising metal salt It is formed with the solution comprising halide salts.Metal oxide layer can halide shell or oxyhalide hull shape at before or during shape At.

II (a) is used to form the synthesis and separation of the metal nanoparticle of core

The metal nano for being used to form shell-slug particle core can be prepared and separated with identical mode described in I (a) Grain.

II (b) hull shape at

Isolated metal nanoparticle is redispersed in aqueous solution under oxygen-free atmosphere.Different from I (a), this is water-soluble Liquid is free of reducing agent.Then under oxygen-free atmosphere, by the mixture comprising isolated metal nanoparticle be used to receive Metal salt and the halide salts mixing of metal halide shell are formed on rice grain core.It should be appreciated that the shape on metal nanoparticle At metal oxide layer can be formed before or during synthesis shell thereon, to prepare CSN, CSN includes comprising being coated with gold Belong to the core of the metallic particles of oxide skin(coating) and coats the shell of the metal oxide layer of the core.

In some embodiments, metal salt is selected from alkali metal salt, alkali salt and transition metal salt.In certain implementations In scheme, metal salt is selected from lanthanum salt, cerium salt and magnesium salts.

Illustrative metal for core includes but is not limited to iron, cobalt, nickel, copper and lead.In a non-limiting example, core By being coated with Cu oxide (CuO_x) copper metal constitute.In a non-limiting example, CuO_xFor CuO₂.For showing for shell Example property compound includes CeF₃、CeOF、LaF₃And LaOF.

II (c) experimental example 2

Synthesize CSN, CSN include comprising coated with copper oxide copper nano particles core and comprising cover Cu oxide layer Lanthanum fluoride shell (Cu/CuO_x/LaF₃).Experimental example 2 carries out identically as experimental example 1, the difference is that general~50nm copper nanometer Grain is not in the case where having reducing agent and is redispersed in water under an argon.There is no reduction during shell forming step In the case where agent, when being similarly formed shown in shell and Fig. 3 B, the outer surface of copper nano particles is converted to Cu oxide layer.

As shown in Figure 11, the XRD spectrum of the CSN synthesized in experimental example 2 shows 6 peaks (° 2 θ): 36.5 (Cu₂O)、42.3 (Cu₂O)、43.5(Cu)、50.4(Cu)、61.5(Cu₂O)、74.0(Cu₂O)。

Including comprising being coated with Cu₂The core of O layers of Cu nano particle and include coating Cu₂O layers of LaF₃Shell gained Core-shell particle can be used as catalyst, and can be included as the electrochemistry electricity by carbon dioxide conversion at Organic Ingredients A part of the cathode in pond.LaF₃Shell can protect the active catalyst sites of core, while increase the CO that can be used for converting₂Office Portion's concentration.

It III. include the CSN of modified metal core and metal halide shell or metal oxyhalide shell

In one embodiment, CSN is provided comprising the core comprising metal oxide nanoparticles and at least partly The shell of ground coating core.Shell includes metal halide shell or metal oxyhalide shell.

It in one illustrative example, can include CSN in the electrode of electrochemical cell to be used for carbon dioxide conversion At Organic Ingredients.Without being bound by any particular theory, the formation of metal oxide can improve core-shell catalyst in electrochemistry electricity Selectivity and catalytic activity in pond.Can be controlled during the synthesis of nanoparticle core and/or shell the formation of metal oxide with Generate desired specificity of catalyst.

CSN can be by converting metal oxide nanoparticles for metal nanoparticle, and by including metal salt Solution and solution comprising halide salts in mix, shell is formed on metal oxide particle to be formed.Metal nanoparticle Can with metal salt and be formed on before or after the halide salts of shell mix and be converted to oxide.

The synthesis and separation of III (a) modified metal core

The gold for being used to form shell-slug particle core can be prepared and separated with identical mode described in I (a) and II (a) Metal nano-particle.Then, isolated metal nanoparticle is modified to convert metal oxide nano for metal nanoparticle Particle.It in a non-limiting example, can be by being redispersed in metal nanoparticle in the aqueous solution without reducing agent simultaneously It is exposed to mixture in oxygen-containing atmosphere, metal nanoparticle is converted at least partly into metal oxide nanoparticles.

III (b) hull shape at

In addition to this or alternatively, by receiving metal during the formation of metal halide shell or metal oxyhalide shell Rice grain is exposed in oxygen-containing atmosphere, isolated metal nanoparticle can be converted to metal oxide nanoparticles.For example, can Isolated metal nanoparticle is mixed under an oxygen-containing atmosphere with the solution comprising metal salt and the solution comprising halide salts, with Metal oxide nanoparticles are converted by metal nanoparticle and form metal halide on metal oxide nanoparticles core Object shell or metal oxyhalide shell.It should be appreciated that the oxidation core of core shell structure can be individual particle or its can be it is smaller Metal oxide nanoparticles agglomerate.It is also understood that metal oxide core can be to be hollow, as shown in Figure 1 C.

Illustrative metal for core includes but is not limited to iron, cobalt, nickel, copper and lead.In a non-limiting example, core It is made of copper oxide (CuOx).In a non-limiting example, CuO_xFor CuO₂.Exemplary compounds for shell include CeF₃、CeOF、LaF₃And LaOF.

III (c) experimental example 3

CSN is synthesized, CSN includes copper oxide nanometer particle core and lanthanum fluoride shell.Firstly, at room temperature by the Cu of 2mmol (NO₃)₂·2.5H₂O and 1.87mmol CTAB is dissolved in 75ml water, and adds 0.5ml NH₄OH (28 weight % to 30 weights Measure the NH of %₃Aqueous solution, 14.8M) pH is adjusted to about 10 to 11.Copper nitrate solution is poured into comprising hydrazine under argon gas In water (75ml) solution of (50% to 60% SILVER REAGENT of 3ml), CTAB (1.87mmol) and citric acid (0.38mmol).It will be anti- Mixture is answered to stir 1.5 hours, so that copper nano particles growth maximizes.Separate and wash resulting copper nano particles (~ 50nm).In particular, being mixed and sonicated by the centrifugation of reaction synthetic mixture, decantation, with ethyl alcohol.These steps are weighed again Again twice, it and disperses copper nano particles in 150ml water again under open air.

To addition La (NO in the mixture of water and copper nano particles₃)₃·6H₂O is (in 15ml H₂1mmol in O) and NaF (in 15ml H₂1mmol in O).Reaction mixture is stirred 10 minutes, and is then centrifuged for.Precipitating passes through centrifuge separation, and Pass through XRD analysis.As shown in figure 12, the XRD spectrum of the nano particle of synthesis shows 4 peaks (° 2 θ): 36.5,42.3,61.5 and 73.5, all both correspond to Cu₂O。

Including Cu₂O core and LaF₃The gained core-shell particle of shell can be used as catalyst, and can be included as by two Carbon oxide conversion at the cathode of the electrochemical cell of Organic Ingredients a part.LaF₃Shell can protect the active catalyst position of core Point, while increasing the CO that can be used for converting₂Local concentration.

It IV. include the CSN of metal core and metal halide shell

The synthesis and separation of IV (a) metal core

The metal nano for being used to form the core of CSN can be prepared and separated with identical mode described in I (a) and II (a) Particle.Illustrative metal for core includes but is not limited to iron, cobalt, nickel, copper and lead.In this example, core includes copper.

IV (b) hull shape at

Under oxygen-free atmosphere, a sample (sample 1) of the isolated metal nanoparticle from IV (a) is divided again It dissipates in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water (60mL) of O (1mmol) is molten Liquid, and stir 60 minutes under argon gas.Then sample is separated, discards supernatant liquid, and sample is then redispersed in water In (300mL).With the aqueous solution (60mL) of 6mL/min injection NaF (1mmol).Solution is stirred 60 minutes, and is then separated And it is washed twice with EtOH.

Under oxygen-free atmosphere, another sample (sample 2) of the isolated metal nanoparticle of IV (a) will be come from again It is scattered in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water (60mL) of O (2mmol) Solution, and stir 60 minutes under argon gas.Then sample is separated, discards supernatant liquid, and sample is then redispersed in water In (300mL).With water (60mL) solution of 6mL/min injection NaF (2mmol).Solution is stirred 60 minutes, and is then separated And it is washed twice with EtOH.

Under oxygen-free atmosphere, another sample (sample 3) of the isolated metal nanoparticle of IV (a) will be come from again It is scattered in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water (60mL) of O (4mmol) Solution, and stir 60 minutes under argon gas.Then sample is separated, discards supernatant liquid, and sample is then redispersed in water In (300mL).With water (60mL) solution of 6mL/min injection NaF (4mmol).Solution is stirred 60 minutes, and is then separated And it is washed twice with EtOH.

IV (c) experimental example 4

Firstly, the sample 1 prepare using ICP and EDS analysis according to IV (b), sample 2 and sample 3 (have copper core with LaF₃The CSN of shell) for assessing shell coverage rate.

For assessment shell coverage rate, it is primarily based on the full shell coverage rate of following model evaluation (that is, 100% shell coverage rate), wherein Assuming that the shape of CSN is sphere, it is assumed that the size of core is about 50nm, and assumes LaF₃Shell with a thickness of about 3nm to 5nm.Base In the model, determine that the evaluated full shell coverage rate of each sample corresponds to the LaF of about 12 weight % to 17 weight %₃。

Then, the LaF for including by each of three samples is measured using ICP and EDS₃Amount by weight.Base In these measurement results, determine that sample 1 includes the LaF of about 2.1 weight %₃, sample 2 includes the LaF of about 3.6 weight %₃, and Sample 3 includes the LaF of about 5.7 weight %₃.By by these values and corresponding to the LaF of evaluated full shell coverage rate₃Amount into Row compares, and determines that sample 1 includes about 18% shell coverage rate, sample 2 includes about 34% shell coverage rate, and sample 3 includes About 50% shell coverage rate.

After the shell percentage of coverage for assessing each sample, the CO of research and more each sample₂Absorption and catalytic activity. Also sample is compared with the control comprising naked copper nano particle (that is, with 0% shell coverage rate).

Firstly, measuring the current density of each sample, and then it is compared with control.For these measurements, system Standby battery, the battery have glassy carbon electrode and include 0.1M KHCO₃Electrolyte.The potential of 1.1V is used relative to RHE. The result of these measurements is shown in FIG. 17.Such as can as shown in Figure 17, the sample with about 34% shell coverage rate (that is, sample 2) Highest current density is provided against expectation, this is significantly higher than is mentioned by the sample with about 50% shell coverage rate (that is, sample 3) The current density of confession.

Also measure the CO adsorbed by sample₂Amount (as unit of mg/g).As can seen in Figure 18 A and Figure 18 B, It is related to the current density that it is measured that the absorption behavior of CSN seems.In particular, corresponding to higher CO₂What is adsorbed is increased Shell percentage of coverage is up to about 34% shell coverage rate, and hereafter it seems to significantly reduce.In addition, it has been observed that compared with the control, Sample CSN shows most twice to the CO more than three times₂Absorption.

Finally, by CO is used in the intrinsic catalytic activity of sample and this field₂Other catalyst activities of condensation are compared Compared with.In particular, the CO that will be provided by sample₂Condensation product with by compare provide those of product together with by copper cube (such as Loiudice, Anna et al. " customize copper for C2 product in electrochemistry CO2 reduction for (both 44nm and 63nm) and copper foil Nanocrystal." " applied chemistry world version ", volume 55, the 19th phase, in May, 2016, page 5789 to 5792 (Loiudice, Anna,et al.“Tailoring Copper Nanocrystals towards C2 Products in Electrochemical CO2Reduction.”Angewandte Chemie International Edition,vol.55, No.19, May 2016, pp.5789-5792)) and by copper film (have 3.6 μ m thicks, as described in Ren, Dan et al., " oxidation Carbon dioxide selectivity is electrochemically reduced to ethylene and ethyl alcohol on copper (I) catalyst "." American Chemical Society is catalyzed magazine ", the 5th Volume, the 5th phase, 2015, (Ren, Dan, et al. " the Selective Electrochemical of page 2814 to 2821 Reduction of Carbon Dioxide to Ethylene and Ethanol on Copper(I)Oxide Catalysts.ACS Catalysis, vol.5, no.5,2015, pp.2814-2821 ")) provide those of be compared.Make The gaseous product generated by every kind of catalyst is measured with gas chromatography (GC), and is surveyed using high performance liquid chromatography (HPLC) The amount of alcohol generated by every kind of catalyst is measured, as respectively as shown in Figure 19A and Figure 19B.As can seen in Figure 19 A and 19B, Compared with other catalyst known in the art, sample CSN generates the alcohol product of incrementss and shows inherently urging for enhancing Change activity.It shall also be noted that sample CSN generates the combination of ethyl alcohol and normal propyl alcohol, however catalyst known in the art generates second The combination of alcohol, methanol, propyl alcohol and allyl alcohol.It is higher than other catalyst known in the art that the data indicate that sample CSN is provided Selectivity of product.

It V. include the CSN of metal core and metal hydroxides shell

The synthesis and separation of V (a) metal core

The gold for being used to form the core of CSN can be prepared and separated with identical mode described in I (a), II (a) and IV (a) Metal nano-particle.Illustrative metal for core includes but is not limited to iron, cobalt, nickel, copper and lead.In this example, core includes copper.

IV (b) hull shape at

Under oxygen-free atmosphere, a sample (sample 1) of the isolated metal nanoparticle from V (a) is divided again It dissipates in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water (60mL) of O (0.1mmol) Solution, and stir 60 minutes under argon gas.Then sample is separated, discards supernatant liquid, and sample is then redispersed in water In (300mL).With the aqueous solution of 3mL/min injection hydrazine hydrate (1.5mL) (wherein the volume of water is adjusted to and is equal in total 30mL).Solution is stirred 60 minutes, and then separates and is washed twice with EtOH.

Under oxygen-free atmosphere, another sample (sample 2) of the isolated metal nanoparticle of V (a) will be come from again It is scattered in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water of O (1.0mmol) (60mL) solution, and stir 60 minutes under argon gas.Then sample is separated, liquid is discarded supernatant, and then divides sample again It dissipates in water (300mL).With the aqueous solution of 3mL/min injection hydrazine hydrate (2mL) (wherein the volume of water is adjusted to and is equal in total 30mL).Solution is stirred 60 minutes, and then separates and is washed twice with EtOH.

Under oxygen-free atmosphere, another sample (sample 3) of the isolated metal nanoparticle of V (a) will be come from again It is scattered in aqueous solution (300mL).Into the aqueous solution, while being added includes La (NO₃)₃-6H₂The water (60mL) of O (2mmol) Solution, and stir 60 minutes under argon gas.Then sample is separated, discards supernatant liquid, and sample is then redispersed in water In (300mL).With the aqueous solution (be wherein adjusted to the volume of water and be equal to 30mL in total) of 3mL/min injection hydrazine hydrate (3mL). Solution is stirred 60 minutes, and then separates and is washed twice with EtOH.

V (c) experimental example 5

Firstly, analyzing sample 1, sample 2 and sample 3 according to IV (b) preparation (that is, having in mode described in IV (c) Copper core and La (OH)₃The CSN of shell) for assessing shell coverage rate.According to surveying and determination, sample 1 constitutes about 10% shell coverage rate, sample 2 About 24% shell coverage rate is constituted, and sample 3 constitutes about 47% shell coverage rate.

After the shell percentage of coverage for assessing each sample, studied in mode described in IV (c) and more each sample CO₂Absorption and catalytic activity.

Such as can be seen in Figure 20, the sample with about 10% shell coverage rate (that is, sample 1) provides most against expectation High current density, this is significantly higher than by compareing, with about 24% shell coverage rate sample (that is, sample 2) and have about 47% Shell coverage rate sample (that is, sample 3) provide current density.

Also measure the CO adsorbed by sample₂Amount (as unit of mg/g).Such as can be seen in Figure 21 A and Figure 21 B, CSN Absorption behavior seem similar with the current density that it is measured.In particular, corresponding to higher CO₂The increased shell of absorption covers Lid percentage is up to about 10% shell coverage rate, and hereafter it is reduced.However, provided by the CSN with about 24% shell coverage rate CO₂The CO provided by naked copper nano particle (that is, control) is still greater than in absorption₂Absorption.

Finally, measuring the CO provided by sample in mode described in IV (c)₂Converted product.In particular, can such as scheme Seen in 22, have La (OH)₃The sample CSN of shell generates a certain amount of alcohol product (that is, ethyl alcohol and normal propyl alcohol), is similar to IV Described in CSN generate amount (that is, have LaF₃Shell, as shown in fig. 19b).Accordingly, it is determined that being similar to has LaF₃Shell CSN has La (OH) compared with other catalyst known in the art₃The CSN of shell additionally provide the alcohol product of incrementss and Show the intrinsic catalytic activity of enhancing.

Comparative example 2

Attempt to prepare the CSN including core, core includes the copper nano particles (Cu/LaF coated with the shell comprising lanthanum fluoride₃)。 Comparative example 2 carries out identically as experimental example 1, the difference is that using 1mmolLaCl₃·7H₂O replaces La (NO₃)₃·6H₂O。

The XRD spectrum of the nano particle synthesized in comparative example 2 is shown in Figure 13.XRD spectrum is shown 5 peaks (° 2 θ): 24.5 (LaF₃)、27.6(LaF₃),43.6(Cu),50.5(Cu),74.1(Cu).Therefore, Cu is in LaCl₃It is protected in the reaction process of NaF It stays.

However, the oxidation instruction shell of Cu is not properly formed after the CSN exposure of comparative example 2.Figure 14 is shown sudden and violent After being exposed to air 8 days, 15 days and 22 days, the stacking XRD of the nano particle synthesized in comparative example 2 is composed.It was initially observed at the 8th day Additional peak (° 2 θ): 35.4,36.4,38.8,42.5,44.8,48.7,52.3,61.5,73.5.At least 36.4,42.5, Peak at 61.5 and 73.5 ° of 2 θ meets Cu₂O is formed.The intensity for meeting the peak at 43.6,50.5 and 74.1 ° of 2 θ of Cu also subtracts It is weak.As shown in figure 15, TEM image shows Cu nano particle by LaF₃Unevenly partial mulching, and not with Cu nanometers The LaF of grain association₃.Therefore, LaCl is used₃·7H₂The shell of O preparation does not generate desired core-shell composition, because it will make Cu core It is exposed in the environment of electrochemical cell.In addition, the LaF not associated with Cu nano particle₃It is mixed reducing in the mixture The overall efficiency of any system.

Comparative example 3

Attempt to prepare the CSN including core, core includes the Cu oxide nano particle coated with the shell comprising lanthanum fluoride (CuOx/LaF₃).Comparative example 3 is carried out in a manner of identical with comparative example 2, the difference is that stirring with hydrazine, CTAB and citric acid After 1.5 hours, copper nano particles are not separated with synthetic mixture, and by the LaCl of 1mmol₃.7H₂O is added copper nano particles and closes In resulting mixture.As shown in figure 16, TEM image shows copper nano particles and is broken down into lesser copper nano particles, and core shell Structure is not formed.Therefore, LaCl is used₃·7H₂The shell of O preparation does not generate desired core-shell composition.

Claims

1. a kind of nano particle, the nano particle includes:

The catalysis core assembly surrounded by shell；

Wherein the catalysis core assembly includes at least one catalysis material, and

Wherein the shell includes at least one compound with halogen and/or oxygen atom.

2. nano particle according to claim 1, wherein at least one compound is selected from fluoride, oxide, fluorine Oxide and hydroxide.

3. nano particle according to claim 1, wherein at least one compound also includes metallic atom.

4. nano particle according to claim 3, wherein the metal is selected from lanthanum, calcium, cerium, magnesium and manganese.

5. nano particle according to claim 1, wherein at least one catalysis material includes metal, metal oxidation Object or their combination.

6. nano particle according to claim 1, wherein the catalysis core assembly is solid.

7. nano particle according to claim 6, wherein the catalysis core assembly includes to be coated by the second catalysis material First catalysis material.

8. nano particle according to claim 7, wherein first catalysis material is metal, and described second is catalyzed Material is metal oxide.

9. nano particle according to claim 1, wherein the catalysis core assembly is hollow.

10. nano particle according to claim 9, wherein the catalysis core assembly is the hollow ball comprising metal oxide Body.

11. nano particle according to claim 1, wherein at least one compound is selected from LaF₃、La(OH)₃、 CeF₃、CaF₂、MgF₂、MeF₃、LaOF、CeOF、La₂O₃And CeO₂。

12. nano particle according to claim 1, wherein the shell includes more than one compound.

13. nano particle according to claim 1, wherein the shell fully covers the surface district of the catalysis core assembly Domain.

14. nano particle according to claim 1, wherein the shell parts cover the surface district of the catalysis core assembly Domain.

15. nano particle according to claim 14, wherein the nano particle is covered with about 25% to 45% shell Rate.

16. nano particle according to claim 14, wherein the nano particle is covered with about 1% to 20% shell Rate.

17. a kind of electrochemical cell, the electrochemical cell include:

Anode,

Cathode, and

Liquid electrolyte；

Wherein the cathode includes electro-catalysis component, and the electro-catalysis component includes at least one nano particle, and described at least one Kind nano particle has the catalysis core assembly surrounded by shell；

Wherein the catalysis core assembly being capable of electronation carbon dioxide；And

18. electrochemical cell according to claim 17, wherein when the battery is powered, the battery chemistries reduction two Carbonoxide.

19. electrochemical cell according to claim 17, wherein at least one compound is selected from fluoride, oxidation Object, oxyfluoride and hydroxide.

20. electrochemical cell according to claim 17, wherein at least one compound also includes metallic atom.

21. electrochemical cell according to claim 20, wherein the metal is selected from lanthanum, calcium, cerium, magnesium and manganese.

22. a kind of electrode, the electrode includes electro-catalysis component, and the electro-catalysis component includes nano particle, the nanometer Grain has the catalysis core assembly surrounded by shell；Wherein the catalysis core assembly being capable of electronation carbon dioxide；And wherein institute Stating shell includes at least one compound with halogen and/or oxygen atom.